Nervous build attempt. i need your experienced opnions please

gona try building on for the 1st time so i've been scouring the net and (local shops) on components and parts. so far these are what i came up with. i am not well versed in overclocking stuff. so its one of the factors that affect my choice of components. am hoping this would last 5years or more.

Processor: Intel core i5 2500k

(i feel that if i went with the i7 i wouldnt be maximizing it)

Motherboard: GA-P67A-UD4-B3 P67

(its supports both sli and crossfire. its seems to be a good choice incase i switch gpu brands)

Ram: (2) 2Gb DDR3 2133 G.Skill RipJaws X dual CL9

(seems like a good brand. as far as i know the mobo supports it)

(i read something on the net on this specific memory brand regarding overclocking being unnecessary. not absolutely sure. so i picked this)

Gpu: (1) Saphire Toxic HD 6850 1Gb gDDR5 (11180-03-40R)

gona buy one 1st. and save for the 2nd.
(am not sure of the exact nvidia equivalent. i think its the gtx460. if not what is? not sure of the price difference either. its seems like a good gpu and price)

OS: windows 7 64bit (unsure of what kind yet though)

as for these,
Harddrive:
DVD drive:
Power Supply:
Monitor:

i have absolutely no clue. i feel the choices for these components would probably be ok in the low-mid budget range rather than the high end but as i'v said am not really sure. i hope there would be helpful suggestions on this.

(i had no idea building one for the 1st time would get this tough. darn compatibility issues!!) this would also be my 1st serious purchases too. (*gulp*)

any suggestions, help and comments would be really really very very much appreciated.